IRJET- Non Destructive Testing of Old R.C.C. Framed Structure

International Research Journal of Engineering and Technology (IRJET)

e-ISSN: 2395-0056

Volume: 06 Issue: 04 | Apr 2019

p-ISSN: 2395-0072

www.irjet.net

Non Destructive Testing of Old R.C.C. Framed Structure Dipali M. Kukade1, Apoorva Kitey2, Dr. Dilip P.Mase3 1M.

2

Tech. Student, Department of Civil Engineering, Gurunanak Institute of technology, Nagpur, India.

Assistant Professor, Department of Civil Engineering, Gurunanak Institute of technology, Nagpur, India.

3Chartered Engineer, Nagpur, India.

---------------------------------------------------------------------***---------------------------------------------------------------------

Abstract - In India there are various old structures that are

at the verge of damage. With due course of time the structure becomes weak as the strength of concrete gets reduced. The reasons that can be considered for this reduced strength are poor quality of construction, improper maintenance, improper design mix, unskilled workmanship etc. Therefore the condition and performance of building must be checked from time to time. Non Destructive Testing is the appropriate solution to this issue. It enhances the performance of any existing structure. Non Destructive testing help to assess the health of structure & how much repairs, rehabilitation & retrofitting is required to bring back the structure in safe stable condition. In this case study non destructive testing is adopted to assess the condition and quality of concrete for 30 years old R.C.C. framed structure which is situated Nagpur.

Various NDT methods such as Rebound Hammer Test, Ultrasonic pulse velocity test and Half cell potentiometer test have been performed. Based on all test results & visual inspections it is found that the structure needs to be repair & retrofit.

Key Words: Non Destructive Testing, Rebound Hammer Test, Ultrasonic Pulse Velocity Test, Half Cell Potentiometer Test.

1.INTRODUCTION 1.1 Non Destructive Testing of Structure The Non Destructive Testing (NDT) is a technique that are used to find out the defects in structure with or without destroying any part of the structure.

Non destructive testing offers significant advantages like, defects can be detected without damaging or destroying the part of structural components, the equipments are easy to handle and it gives appropriate results with the help of NDT. It requires to understand the various methods available, their capabilities and limitations, knowledge of the relevant standard and specification for performing the test. These techniques can be used to monitor the reliability of the item of structure throughout its design life.

1.2 Objective of the Case Study The objective of present case study is to obtained the Non Destructive Testing of 30 years old R.C.C. Framed structure with Rebound Hammer Test to know the probable Compressive Strength, Ultrasonic Pulse Velocity Test for access the condition of structure & Half cell Potentiometer Test to know the availability of corrosion in reinforcement and visual inspection.

2. METHODOLOGY 2.1 Visual Inspection Visual inspection is the first step in NDT method to evaluation of concrete structure that are visually accessible, it gives an idea about overall condition of structure when investigate thoroughly. The detail visual inspection were carried out on different members of the structure and we have observed Reinforcement exposed at various location, corrosion, major and minor cracks, honeycombing, deterioration of concrete etc.

As we know concrete reduced strength due to over age of structure, poor quality of construction material, unskilled workmanship, improper maintenance, improper design mix etc. therefore it is necessary to check the condition, quality of concrete & performance of structure from time to time. The Non Destructive testing offers proper solution for these issues.

Š 2019, IRJET

|

Impact Factor value: 7.211

|

ISO 9001:2008 Certified Journal

|

Page 4067

International Research Journal of Engineering and Technology (IRJET)

e-ISSN: 2395-0056

Volume: 06 Issue: 04 | Apr 2019

p-ISSN: 2395-0072

www.irjet.net

Average Rebound 20-30 <20 0

Quality of Concrete Fair Poor concrete Delaminated

Fig -1: Reinforcement exposed, corrosion, cracks observed in Column.

Fig -3: Rebound Hammer Test.

Fig -2: Reinforcement exposed, corrosion, cracks observed in Column.

2.2 Rebound Hammer Test Rebound hammer test is the surface hardness test when the plunger of rebound hammer pressed against the concrete surface it gives the probable compressive strength of concrete.

In 1948 Ernst Schmidt a Swiss Engineer develop a device for testing concrete. The device measures the rebound value R. There is a specific relation between this value and the hardness and strength of concrete.

The rebound numbers are influenced by a number of factors like types of cement and aggregate, surface condition and moisture content, age of concrete and extent of carbonation of concrete. The impact direction of hammer are horizontal, vertically upward or vertically downward. As per IS:13311 Part-2, the probable accuracy of prediction of concrete strength in a structure by rebound hammer test is +/-25%.

TABLE -1: rebound criteria for quality of concrete grading Average Rebound >40

Quality of Concrete Very Good hard layer

2.3 Ultrasonic Pulse Velocity Test Ultrasonic Pulse Velocity Test is used to established the quality of concrete, presence of cracks, voids and other imperfections in structure.

This is one of the most commonly used method in which the ultrasonic pulses generated by electro-acoustical transducer are transmitted through the concrete & measuring the time taken. Distance of path length divided by the transit time gives the pulse velocity of concrete member being tested. The ultrasonic pulse velocity is influenced by path length, lateral dimension of specimen tested, presence of reinforcing steel, and moisture content of the concrete.

The methods of measurements of ultrasonic pulse velocity through concrete are a) Direct Transmission (Cross Probing).

Good

30-40

Fig -4: Rebound Hammer Test.

b) Semi-Direct Transmission c) Indirect Transmission (Surface Probing)

Š 2019, IRJET

|

Impact Factor value: 7.211

|

ISO 9001:2008 Certified Journal

|

Page 4068

International Research Journal of Engineering and Technology (IRJET)

e-ISSN: 2395-0056

Volume: 06 Issue: 04 | Apr 2019

p-ISSN: 2395-0072

www.irjet.net

The instrument used for testing is Pundit Lab (30610001) UPV Instrument (Proceq) (Made in Switzerland).

TABLE -2: Velocity Criteria for Quality of Concrete Grading Pulse Velocity Above 4.5 Km/Sec 3.5 - 4.5 Km/Sec 3.0 - 3.5 Km/Sec Below 3.0 Km/Sec

Quality of Concrete Excellent Good Satisfactory

Fig -7 Schematic View of Half Cell Potentiometer [http://civilonline2010.blogspot.com/2010/09/half-cell-electricalpotential-method.html]

Doubtful

TABLE -3: Corrosion Condition of Reinforcing Bar Copper / Copper Sulphate > -200 mV

Corrosion Condition Low ( 10% chances )

-200 to -350 mV

Intermediate

< -350 mV

High ( <90 % )

< -500 mV

Severe Corrosion

Fig -5 Ultrasonic Pulse Velocity Test Machine.

Fig -8 Half Cell Potentiometer Test.

3. TEST RESULTS 3.1 Rebound Hammer Test Results Sr. No.

Fig -6 Ultrasonic Pulse Velocity Test.

Description

No. of Points

2.4 Half Cell Potentiometer Test

Ground Floor

Half cell potentiometer test is used determine the probability of corrosion associated with steel in concrete.

The apparatus given by ASTM C876 which include copper/Copper Sulphate electrode or silver / silver chloride electrode for half cell test.

Half cell makes electrical contact with concrete by means of porous plug and sponge. One end of wire is connected to steel reinforcement and other end is connected to standard electrode and readings are noted as seen on voltmeter. More negative value indicated the higher is the bar corrosion. Š 2019, IRJET

|

Impact Factor value: 7.211

Rebound Hammer Test Max. Min. Average

|

1.

2.

3.

Column

114

31.67

15

23.33

Beam

18

30.33

27

28.66

Slab

12

29.66

29.33

29.49

29

30

First Floor 4.

Column

12

ISO 9001:2008 Certified Journal

31

|

Page 4069

International Research Journal of Engineering and Technology (IRJET)

e-ISSN: 2395-0056

Volume: 06 Issue: 04 | Apr 2019

p-ISSN: 2395-0072

www.irjet.net

3.3 Half Cell Potentiometer Test Results

Second Floor 5.

Column

14

32.57

31.71

32.14

Third Floor

6.

Column

12

33.66

Half Cell Potentiometer Test Sr. No.

32

Average Description

32.83

Fourth Floor 7.

Column

12

36

32

34

1.

As per Rebound Hammer Test results it is observed that maximum readings are confirming to M10 to M15 grade of concrete that indicated the poor quality of concrete.

Description

No. of Points

3.

4.

3.2 Ultrasonic Pulse Velocity Test Results Sr. No.

2.

Ultrasonic Pulse velocity Test (Km/SEC) Max. Min. Average

5.

6.

Ground Floor 7.

1.

2.

3.

Column

98

3.53

1.4

2.46

Beam

20

1.98

1.13

1.55

Slab

17

2.3

1.4

1.85

First Floor 4.

Column

7

2.3

1.87

2.08

Second Floor 5.

6.

12

2.3

1.33

1.81

Beam

4

1.94

1.87

1.90

2.47

2.88

2.83

3.06

Column

10

3.3 Fourth Floor

8.

Column

14

3.3

As per Ultrasonic Pulse Velocity test results it is observed that maximum readings are below 3.0 Km/sec that indicated the quality of concrete is doubtful.

Š 2019, IRJET

|

Column No..-C2 Column No..-C8 Column No..-C9 Column No..-C12 Column No..-C16 Column No..-C17 Column No..-C21

-355, -346, -321, 272, -241, -232, -223, -216, -168 -319, -317, -315, 250, -247, -240, -238, -224, -212 -341, -333,-321,-308, -302,-291,-279,-269, -263 -360, -359, -341, 332, -258, -245, -235, -218, -217 -501, -499, -418, 400, -397, -357, -348, -345, -343 -399, -320, -318, -305, -242, -237, -236,-211, -209 -339, -321, -315, 301, -297, -295, -287, -279, -277 -458, -441, -435, 408, -397, -391, -383, -380, -371

(mV)

-263

-262 -300 -285 -400 -275 -301 -407

As per Half cell Potentiometer Test results maximum readings are in between -262 and -407 that indicate there is severe corrosion at most of the locations.

4. CONCLUSIONS

Column

Third Floor 7.

8.

Column No..-C1

Half Cell Readings (mV)

Impact Factor value: 7.211

|

In this paper various Non Destructive Tests have been performed on existing structure such as Rebound Hammer Test, Ultrasonic Pulse Velocity Test and Half cell Potentiometer Test including visual inspection.

As per the visual inspection, Rebound Hammer test & Ultrasonic Pulse velocity test results it is observed that various columns readings whose strength and quality of concrete is doubtful for such columns jacketing should be done.

According to the half cell potentiometer test results severe corrosion are observed at most of the location.

Test results Conclude that Repairs and Retrofitting should be done as per the specification to maintain the existing structure in good condition.

ISO 9001:2008 Certified Journal

|

Page 4070

International Research Journal of Engineering and Technology (IRJET)

e-ISSN: 2395-0056

Volume: 06 Issue: 04 | Apr 2019

p-ISSN: 2395-0072

www.irjet.net

ACKNOWLEDGEMENT I would like to express my sincere thanks to the Assistant Pofessor Apporva Kitey and Dr. Dilip Mase, Director, P. T. Mase & Associates to give me this opportunity to work for this project and technical support on “Non Destructive Testing of Old R.C.C. Framed Structure" It would have been possible to the kind support and help of them.

REFERENCES [1]

Prof. Dr. D. K. Kulkarni, Mr. Teke Sudhakar S., "Health Assessment of Reinforced Concrete Structures - A Case Study" IOSR Journal of Mechanical & Civil Engineering (IOSR-JMCE), ISSN:2278-1684, PP:37-42.

[2]

Namita R. Jain, Mr. K. N. Vishwanath., "Strength Assessment & Restoration of RC Structure by Structural Health Evaluation -Case Study". International Journal of Engineering Research & Technology (IJERT), ISSN:22780181, Vol.2 Issue 7, 2013.

[3]

Kondapalli Harshda, K. Sundara Kumar. "Non Destructive Evaluation of Structural Health of a Building Using Rebound Hammer" International Research Journal of Engineering & Technology (IRJET), e-ISSN:23950056, p-ISSN:2395-0072, Vol.2 Issue:09,2015.

[4]

Dhananjay Mangrulkar, Manoj Chauhan, Shubham Kadam, Saurabh Likhare. "Case Study of RCC Structure with the help of Non Destructive Testing". International Research Journal of Engineering & Technology (IRJET) , e-ISSN: 2395-0056, p-ISSN: 2395-0072 Vol.5 Issue:03, 2018.

[5]

Nikhil L. Jagtap, Prof. P. R. Mehetre, "Study on Retrofitted R.C.C. Building by Different NDT Methods".

IOSR Journal of Mechanical & Civil Engineering (IOSRJMCE) e-ISSN:2278-1684, p-ISSN:2320-334X, Vol.12, Issue: 3 Ver-I,2015.

[6]

Mrs. L. Chandrakanthamma M>E., Deepashree A.B., Madhan ISP, Mohommad Habil.N, Vishvanathan.R.C, "Assessment of Concrete Strength on structure using Non Destructive Testing" IOSR Journal of Mechanical & civil Engineering (IOSR-JMCE) e-ISSN:2278-1684, pISSN:2320-334X, PP 01-04.

[7]

Indian Standards, IS 13311:1992 (Part-I), "Non Destructive Testing of Concrete-Methods of Tests, Ultrasonic Pulse Velocity".

[8]

Indian Standards, IS 13311:1992 (Part-II), "Non Destructive Testing of Concrete-Methods of Tests, Rebound Hammer Test".

[9]

British Standard, BS 1881: Part 201:1986, Guide to the use of non-destructive methods of test for hardened concrete.

© 2019, IRJET

|

Impact Factor value: 7.211

|

ISO 9001:2008 Certified Journal

|

Page 4071